My beef with them is they made up the 97% consensus thing, which when you look at the "study" they did, it's absolute trash science. And they've been shouting it form the rooftops for years.
Nice of you to imagine reasons for my dislike of them before I had a chance to answer though. Classy.
Here is one explanation why it is trash science, but you can google yourself and find many many more that all point to the same thing.
https://www.forbes.com/sites/alexeps.../#530a1f573f9f